Problem: If $x \boxdot y = x^{2}-2y^{2}$ and $x \otimes y = (3-x)(y)$, find $(1 \otimes -2) \boxdot 2$.
Explanation: First, find $1 \otimes -2$ $ 1 \otimes -2 = (3-1)(-2)$ $ \hphantom{1 \otimes -2} = -4$ Now, find $-4 \boxdot 2$ $ -4 \boxdot 2 = (-4)^{2}-2(2^{2})$ $ \hphantom{-4 \boxdot 2} = 8$.